| 摘要 |
PURPOSE:To improve magnet characteristics such as residual flux density, coercive force, etc., by manufacturing a permanent magnet by using an alloy ingot being prepared by controlling the degree of supercooling and cooling rate of an alloy melt and having a specific crystalline structure as an essential raw material component through specific manufacture. CONSTITUTION:An alloy melt containing a 25-31wt.% rare earth metal, 0.5-1.5wt.% boron and iron is coagulated uniformly under the cooling conditions of the degree of supercooling of 50-500 deg.C and a cooling rate from 500 deg.C/sec to 10000 deg.C/sec through a single roll method. A raw material component mainly comprising an alloy ingot containing not less than 90vol.% columnar crystals having columnar-crystal grain size of the minor axis direction of 0.1-50mum and the major axis direction from 100mum to 300mum acquired through the manufacture is ground, molded and sintered, thus manufacturing a permanent magnet. Accordingly, the permanent magnet, in which the conditions of grinding at the time of production are facilitated and which has excellent magnetic characteristics such as residual flux density, coercive force, etc., and particularly has superior anisotropic characteristics, can be acquired. |
